The Quality of Care Measurement and Analysis Core is proposed as a central unit that will support all aspects of the Education, Epidemiology, and Health Services Research (EEHSR) Component of the MAMDC. It will serve as a center for the development of methodological and analytical strategies regarding health status and quality of care for all of the health services research projects associated with the MAMDC work. It will assure the use of similar and consistent methods and strategies across projects so that we may have economies of scale in the sample, analyses and budget. The Core proposes to adapt a standard, conceptual framework and previously validated set of methodologies for measuring quality of care to the discipline of rheumatology, specifically to patients with rheumatoid arthritis (RA). This will involve the application by the Core of the principles of structure, processes, and outcomes of care to patients with new rheumatoid arthritis in two associated research projects. The Core and these research projects collectively define the research segment of MAMDC's EEHSR (Epidemiology, Education, and Health Services Research) Component. In conjunction with this Core, the EEHSR also submits two associated research projects. The Claims Data Project (MacLean/Kahn), which will be served by the Core, will assess the performance characteristics of claims based quality of care measures in a single large managed care organization. The Practice Pattern Project (Rubensten/Wong) which will also be served by the Core, will assess quality of care in practice patterns defined by types of providers (i.e., predominantly primary care or predominantly rheumatologist) in three managed care settings. Though individual projects will have their own unique study questions, they will interact substantially as mediated by the Core.